stream: pipeTo treats writer transform() method as pipeline transform #63683

Closed
#63684
Closed
stream: pipeTo treats writer transform() method as pipeline transform#63683
#63684
Assignees
trivikr
Labels
streamIssues and PRs related to Node.js streams.

Description

@trivikr
trivikr
opened on May 31, 2026

Version

26.2.0

Platform

macOS 26.5.0

Subsystem

stream

What steps will reproduce the bug?

import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior? Why is that the expected behavior?

hello

The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.

What do you see instead?

BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)

pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.

Additional information

No response

Activity

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    , 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
     blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

    Skip to content
    stream: pipeTo treats writer transform() method as pipeline transform #63683
    Closed
    #63684
    Closed
    stream: pipeTo treats writer transform() method as pipeline transform#63683
    #63684
    Assignees
    trivikr
    Labels
    streamIssues and PRs related to Node.js streams.
    Description
    @trivikr
    trivikr
    opened on May 31, 2026
    Version
    26.2.0
    Platform
    macOS 26.5.0

    Subsystem
    stream
    What steps will reproduce the bug?
    import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));
    How often does it reproduce? Is there a required condition?
    Always
    What is the expected behavior? Why is that the expected behavior?
    hello
    The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.
    What do you see instead?
    BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
    pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.
    Additional information
    No response
    Activity
    Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
    Metadata
    Metadata
    Assignees
    Labels
    streamIssues and PRs related to Node.js streams.
    Type
    No type
    Projects
    No projects
      Milestone
      No milestone
      Relationships
      None yet
      Development
      No branches or pull requests
      Issue actions
      
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

      Skip to content
      stream: pipeTo treats writer transform() method as pipeline transform #63683
      Closed
      #63684
      Closed
      stream: pipeTo treats writer transform() method as pipeline transform#63683
      #63684
      Assignees
      trivikr
      Labels
      streamIssues and PRs related to Node.js streams.
      Description
      @trivikr
      trivikr
      opened on May 31, 2026
      Version
      26.2.0
      Platform
      macOS 26.5.0

      Subsystem
      stream
      What steps will reproduce the bug?
      import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));
      How often does it reproduce? Is there a required condition?
      Always
      What is the expected behavior? Why is that the expected behavior?
      hello
      The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.
      What do you see instead?
      BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
      pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.
      Additional information
      No response
      Activity
      Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
      Metadata
      Metadata
      Assignees
      Labels
      streamIssues and PRs related to Node.js streams.
      Type
      No type
      Projects
      No projects
        Milestone
        No milestone
        Relationships
        None yet
        Development
        No branches or pull requests
        Issue actions
        
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

        Skip to content
        stream: pipeTo treats writer transform() method as pipeline transform #63683
        Closed
        #63684
        Closed
        stream: pipeTo treats writer transform() method as pipeline transform#63683
        #63684
        Assignees
        trivikr
        Labels
        streamIssues and PRs related to Node.js streams.
        Description
        @trivikr
        trivikr
        opened on May 31, 2026
        Version
        26.2.0
        Platform
        macOS 26.5.0

        Subsystem
        stream
        What steps will reproduce the bug?
        import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));
        How often does it reproduce? Is there a required condition?
        Always
        What is the expected behavior? Why is that the expected behavior?
        hello
        The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.
        What do you see instead?
        BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
        pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.
        Additional information
        No response
        Activity
        Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
        Metadata
        Metadata
        Assignees
        Labels
        streamIssues and PRs related to Node.js streams.
        Type
        No type
        Projects
        No projects
          Milestone
          No milestone
          Relationships
          None yet
          Development
          No branches or pull requests
          Issue actions
          
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

          Skip to content
          stream: pipeTo treats writer transform() method as pipeline transform #63683
          Closed
          #63684
          Closed
          stream: pipeTo treats writer transform() method as pipeline transform#63683
          #63684
          Assignees
          trivikr
          Labels
          streamIssues and PRs related to Node.js streams.
          Description
          @trivikr
          trivikr
          opened on May 31, 2026
          Version
          26.2.0
          Platform
          macOS 26.5.0

          Subsystem
          stream
          What steps will reproduce the bug?
          import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));
          How often does it reproduce? Is there a required condition?
          Always
          What is the expected behavior? Why is that the expected behavior?
          hello
          The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.
          What do you see instead?
          BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
          pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.
          Additional information
          No response
          Activity
          Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
          Metadata
          Metadata
          Assignees
          Labels
          streamIssues and PRs related to Node.js streams.
          Type
          No type
          Projects
          No projects
            Milestone
            No milestone
            Relationships
            None yet
            Development
            No branches or pull requests
            Issue actions
            
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

            Skip to content
            stream: pipeTo treats writer transform() method as pipeline transform #63683
            Closed
            #63684
            Closed
            stream: pipeTo treats writer transform() method as pipeline transform#63683
            #63684
            Assignees
            trivikr
            Labels
            streamIssues and PRs related to Node.js streams.
            Description
            @trivikr
            trivikr
            opened on May 31, 2026
            Version
            26.2.0
            Platform
            macOS 26.5.0

            Subsystem
            stream
            What steps will reproduce the bug?
            import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));
            How often does it reproduce? Is there a required condition?
            Always
            What is the expected behavior? Why is that the expected behavior?
            hello
            The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.
            What do you see instead?
            BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
            pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.
            Additional information
            No response
            Activity
            Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
            Metadata
            Metadata
            Assignees
            Labels
            streamIssues and PRs related to Node.js streams.
            Type
            No type
            Projects
            No projects
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

              Skip to content
              stream: pipeTo treats writer transform() method as pipeline transform #63683
              Closed
              #63684
              Closed
              stream: pipeTo treats writer transform() method as pipeline transform#63683
              #63684
              Assignees
              trivikr
              Labels
              streamIssues and PRs related to Node.js streams.
              Description
              @trivikr
              trivikr
              opened on May 31, 2026
              Version
              26.2.0
              Platform
              macOS 26.5.0

              Subsystem
              stream
              What steps will reproduce the bug?
              import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));
              How often does it reproduce? Is there a required condition?
              Always
              What is the expected behavior? Why is that the expected behavior?
              hello
              The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.
              What do you see instead?
              BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
              pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.
              Additional information
              No response
              Activity
              Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
              Metadata
              Metadata
              Assignees
              Labels
              streamIssues and PRs related to Node.js streams.
              Type
              No type
              Projects
              No projects
                Milestone
                No milestone
                Relationships
                None yet
                Development
                No branches or pull requests
                Issue actions
                
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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                stream: pipeTo treats writer transform() method as pipeline transform #63683
                Closed
                #63684
                Closed
                stream: pipeTo treats writer transform() method as pipeline transform#63683
                #63684
                Assignees
                trivikr
                Labels
                streamIssues and PRs related to Node.js streams.
                Description
                @trivikr
                trivikr
                opened on May 31, 2026
                Version
                26.2.0
                Platform
                macOS 26.5.0

                Subsystem
                stream
                What steps will reproduce the bug?
                import{pipeTo,from}from'node:stream/iter';constchunks=[];constwriter={transform(){console.log('BUG: writer.transform() was called');returnnull;},write(chunk){chunks.push(newTextDecoder().decode(chunk));},};awaitpipeTo(from('hello'),writer);console.log(chunks.join(''));
                How often does it reproduce? Is there a required condition?
                Always
                What is the expected behavior? Why is that the expected behavior?
                hello
                The final pipeTo() argument should be treated only as the destination writer; transform objects are only the arguments before the writer.
                What do you see instead?
                BUG: writer.transform() was callednode:internal/streams/iter/pull:584 for await (const item of output) { ^TypeError: Cannot read properties of null (reading 'Symbol(Symbol.asyncIterator)') at applyStatefulAsyncTransform (node:internal/streams/iter/pull:584:28) at applyStatefulAsyncTransform.next (<anonymous>) at createAsyncPipeline (node:internal/streams/iter/pull:703:22) at createAsyncPipeline.next (<anonymous>) at pipeTo (node:internal/streams/iter/pull:1000:26) at file:///Users/trivikram/workspace/test-repro/repro.js:15:7 at ModuleJob.run (node:internal/modules/esm/module_job:439:25) at process.processTicksAndRejections (node:internal/process/task_queues:104:5) at async node:internal/modules/esm/loader:646:26 at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)
                pipeTo() calls writer.transform() when the destination writer object also has a transform() method, so the writer is treated as a transform as well as the destination.
                Additional information
                No response
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